<html>
<head>
<title></title>
<link href="http://cdn.bootcss.com/bootstrap/3.3.6/css/bootstrap.min.css" rel="stylesheet"></head>
<body>
<h2>hello, </h2>
<form action="/login" method="post">
    <input type="hidden" value="{{.}}">
    用户名:<input type="text" name="username">
    密码:<input type="password" name="password">
    <input type="submit" value="登陆">
</form>
</body>
</html>